Question

Assertion :Derivative of $3\cot x+5\text{cosec}x$ is $-\text{cosec}x(3\text{cosec}x+5\cot x)$ Reason: $f^{\prime }\left(a\right)=\underset{h\to 0}{lim}\frac{f(a+h)-f\left(a\right)}{h}$

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

$y=3\cot x+5co\sec x$

$\frac{dy}{dx}=-3{co\sec }^{2}x-5co\sec x.\cot x=-co\sec x(3co\sec x+5\cot x)$

Therefore, option A is correct.